Fluid dampers are well-known devices designed to attenuate disturbance forces (e.g., vibrations or impact loads) by forcing damping fluid through a restricted flow path, such as an annulus. Fluid dampers are commonly produced to have a constant or fixed annulus, which does not vary in size or shape during operation of the damper. As a result, the damping coefficient of the damper varies in conjunction with changes in damping fluid viscosity, which, in turns, varies with fluctuations in damping fluid temperature. In applications wherein the operative temperature range of the damper is relatively limited, such changes in damping coefficient are often minimal and generally non-consequential. However, in applications wherein the fluid damper is exposed to a relatively broad operative temperature range, undesirably large changes in the damping coefficient of the fluid damper may occur if measures are not taken to compensate for thermally-induced fluctuations in damping fluid viscosity. While certain fluid damper designs have been proposed to address thermally-induced changes in damping fluid viscosity, such designs tend to be limited in one or more respects. For example, fluid dampers have been developed that incorporate materials (e.g., plastics) having relatively large coefficients of thermal expansion (CTEs), which can be leveraged to adjust radial width of an annulus or other restricted flow path as a function of damping fluid temperature; however, the volumetric expansion or contraction of such high CTE materials is still typically inadequate to fully compensate for the relatively large changes in damping fluid viscosity that may occur over a broad operative temperature range, such as an operative temperature range approaching or exceeding 100° Celsius (° C.). Additionally, plastics and other high CTE materials may be subject to undesirable temperature limitations.
There thus exists an ongoing need to provide embodiments of a fluid damper having an improved temperature-dependent viscosity compensation device (referred to herein more simply as a “viscosity compensator”). Ideally, such a viscosity compensator would operative passively and compensate, at least in substantial part, for thermally-induced changes in damping fluid viscosity to minimize fluctuations in damping coefficient over a relatively broad operative temperature range of the fluid damper. It would also be desirable if such a viscosity-compensated fluid damper could be produced as a standalone device or, alternatively, incorporated into a multi-parameter isolator, such as a three parameter isolator. Other desirable features and characteristics of embodiments of the present invention will become apparent from the subsequent Detailed Description and the appended Claims, taken in conjunction with the accompanying drawings and the foregoing Background.